1. Technical Field
The present invention relates to an actuator, an optical scanner and an image forming apparatus.
2. Related Art
As an optical scanner used for drawing by utilizing optical scanning in a printer or the like, there is known one performing two-dimensional scanning (see, for example JP-A-08-322227).
The optical scanner disclosed in JP-A-08-322227 has a scanner main body including a frame-like outer movable plate, a pairs of first torsion bars axially supporting the outer movable plate so that the outer movable plate is swingably supported (rotatable) about an X axis, an inner movable plate provided inside the outer movable plate, a pair of second torsion bars axially supporting the inner movable plate so that the inner movable plate is swingable about a Y axis orthogonal to the X axis, a pair of driving coils respectively provided in the outer movable plate and the inner movable plate, and a pair of permanent magnets provided so as to oppose each other through the intermediation of the scanner main body.
In such the optical scanner, however, the permanent magnets are provided so as to be opposite to each other through the intermediation of the scanner main body, so miniaturization of the light scanner can hardly be achieved. Further, the outer movable plate and the inner movable plate are respectively provided with one driving coil, so it is difficult to achieve cost reduction.